Rectilinear motion device for a mechanical handling machine

ABSTRACT

A rectilinear motion device which includes a mechanical arm having a pair of links or levers which extend and retract. The two levers are joined together at an elbow mechanism. The two levers extend at equal angles with respect to a reference line through the elbow mechanism. The ends of the two levers are respectively fixed with regard to the structure of the device and extensible to carry an arm which preferably maintains a planar position and which extends and retracts with the pair of levers.

United States Patent 1 214/1 CM, 1 BB, 772, 769

[ 11 3,731,820 Niki et a]; 51 May 8, 1973 [54] RECTILINEAR MOTION DEVICEFOR [56] References Cited A MECHANICAL HANDLING MACHINE UNITED STATESPATENTS 7 Inventors: Akiri ki i Satoshi Hirose 521,256 6/1894 Browne..74/521 X wakabaya; Jiro ohara, g y 1 3,268,092 8/1966 Hamer et al..2|4/] CM of Japan Primary Examiner-Milton Kaufman ['73] Assignee:Nagoya Kiko Co., Ltd., Negoya, An0mey Dona]d Japan [22] Filed: July 6,1970 [57] ABSTRACT [2]] Appl. No.: 52,396 A rectilinear motion devicewhich includes a mechanical arm having a pair of links or levers whichextend [30] Foreign Applicafion Priority Data and retract. The twolevers are joined together at an elbow mechanism. The two levers extendat equal an- July 8, 1969 Japan ..44/53947 gles with respect to areference line through the elbow June 10, 1970 Japan ..45/50l42mechanisn The ends of the two ]evers are respective. ly fixed withregard to the structure of the device and [52] U.S. Cl ..2l4/l BB,74/469 extensible to carry an arm which l maintains [51] Int. Cl ..B66c1/42 a planar position and which extends and retracts with [58] Field ofSearch ..74/469, 491, 521;

the pair of levers.

9 Claims, 10 Drawing Figures Patented May 8, 1973 '7 Sheets-Sheet 1 vPatented May'S, 1973 '7 Sheets-Sheet 2 Patented May 8, 1973 '7Sheets-Sheet 5 Patn fed May 8, 1973 7 Sheets-Sheet 4 Patented May 8,1973 3,731,820

'7 Sheets-Sheet 5 BY Ww A'ITORNEY Paten ted May 8, 1973 '7 Sheets-Sheet6 Patented May 8 1973 '7 Sheets-Sheet 7 SUMMARY OF PROBLEM AND SOLUTIONThe present invention relates to a rectilinear motion device for use ina mechanical handling machine. In the handlingof materials in anenvironment subjected to gaseous fumes, radiation, excessive heat, andother elements, it is quite often difficult to obtain personalassistance. Consequently, a mechanical handling device or machine ispreferably used. However, such a mechanical handling machine typicallyincludes arms which are articulated, for extension and retraction,either free and unsupported in space, or for movement guided by a railor other mechanism. When the arm extends freely in space, quite oftenits motion is not rectilinear, and hence, control of the machine toreach and grasp is somewhat difficult. When movement of the device iscontrolled by rails or other track mechanisms, additional expense andcomplexity are added.

Consequently, the present invention has as one goal the provision of anew and improved, compact, smoothly acting device for causing the arm ofa mechanical handling machine to move along a horizontal straight linewithout the aid of rails or other guide mechanisms. The presentinvention is summarized as including a supporting structure for the arm,which is comprised of a horizontal, extended portion, and a pair ofmovable links or levers. The two levers connect at an elbow. The elbowis so constructed that the angle of the two levers with respect to theelbow, remains equal during extension or retraction of the arm. The twolevers are pivotally connected at the lower ends. One is pivotallyconnected on a shaft with a crank throw connected with a hydrauliccylinder. The hydraulic cylinder rotates the crank which, in turn,rotates the shaft and the lever. This causes the first lever to rotateto an angle, and through operation of the elbow, the second lever ismaintained at a like angle. The second lever is connected at its freeend to the forearm portion of the machinery. Thisthereby achievesextension of the arm. i V

Many objects, features and advantages of the present invention will bereadily understood from the following written description of thepreferred embodiments of mediate positions of the arm between the fullyretracted position and the fully extended position;

FIG. 5 is a side view of another embodiment of the mechanical handlingapparatus of the present invention shown in its retracted position;

FIG. 6 is a right hand side view of still another embodiment of thedevice according to the present invention in which the arm of themechanical handling machine is shown in its retracted position;

F IG. 7 is a left sideview of the embodiment shown FIG. 6; o y

F IG. 8 is a front view of the structure shown in FIGS. 6 and 7;

FIG. 9 isa sectional view taken along the line Y Y in FIG. 6; and,

FIG. 10 is a schematic diagram showing various intermediate positions ofthe arm extended by the embodiment shown in FIGS. 6 9.

Attention is first directed to FIGS. 1, 2 and 3 of the drawings whichshow a first embodiment of the device of the present invention. In FIG.1, a support structure 1 which is generally in the form of a rectangularbox, incorporates a bottom plate 2 which supports a bracket 3having apair of upstanding members. The upstanding members of the bracket 3support the ends of a rotatable shaft 4.; The rotatable shaft is.preferably journaled and supported in appropriate bearings. The shaft 4supports a lever 5 held in its normal upright position of FIG. 1. Thelever 5 is the first movable segment of the entirety of the mechanicalarm. The lever 5 is of rectangular construction and is gussetted orreinforced for strength. Other constructions can be used equally well.

The lever 5 is fixed to the shaft 4. Additionally,a crank arm 6extendsupward and "to the left at an angle as shown in FIG. 1. The crankarm is common to the shaft 4. Consequently, the shaft 41, the lever 5,and the crank 6 rotate as a unit about an axis of rotation determined bythe joumaled support of the shaft 4 in the bracket 3. The crank 6 isoffset at its end portion as best shown in FIG. 3. This locates the endof the crank 6 off to the side and somewhat remote from the severalcomponents of the extendible arm as will be described. This then permitsaccess to the crank 6 for actuation in a manner to be describedhereinafter.

The box like structure 1 preferably incorporates upstanding verticalmembers extending from the bottom plate 2 and which support a top plate7. The top plate 7 supports a fixed mounting plate 8 on its nether sideas shown in FIG. 1. The fixed mounting plate incorporates a pair ofdownwardly pointed, bifurcated brackets which support the upper end ofthe vertically mounted hydraulic cylinder 9. The hydraulic cylinder 9incorporates a piston rod 10 which is extendible upwardly anddownwardly. The hydraulic cylinder 9 is pivotally connected by means ofa pin 11 extending through the bracket 8 as shown in FIG. 1. At thelower end, the piston rod 10 is pivotally connected to the crank 6 bymeans of the pin 12.Beingpin connected at each end, the hydrauliccylinder is free to rotate to an angle determined by movable componentsof the present invention.

The lever 5 is arcuately curved or rounded at its upper end as shown inFIG. 1. More importantly, the

lever 5 carries a sector gear 13 on its upper end, and a sector gear 14is adapted to engage with the sector gear 13. The gear 14 is carried onthe upper end of an additional lever 15. The gears 13 and 14 are fixedrespectively on shafts 1'8 and 19 near the bottom edge 17 of atrapezoidal connecting member or elbow 16. The gears 13 and 14preferably mesh and are preferably shaped like one another. The levers 5and 15 are adapted to rotate to the same extent, but in oppositedirections with respect to the elbow 16. The levers 5 and 15 are ofsymmetrical construction to one another. Moreover,

they are the same length. Additionally, they are connected to theseveral rotatable shafts as illustrated in FIG. 1, and the shafts arepreferably identical, one to the other.

As shown in FIG. 3, the crank arm 6 is located somewhat toward the backside of the equipment. As also shown in FIG. 1, a fixed arm 20 islocated on the front side of the equipment and fixed to the bracket 3 soas to extend upwardly at an angle as illustrated. The lower end of a rod22 is connected to the fixed mounting arm 20 which is carried on thesupport bracket 3. The upper end of the rod 22 is pivotally connected toa cross bar 21 which is carried on and made integral with the elbow 16.It should be kept in mind that the elbow 16 is somewhat U-shaped incross section, and is inverted in its normal installed position ofFIG. 1. It has a lower edge 17 previously mentioned. Extending acrossthe stiff horizontal back member as viewed from the side in FIG. 1, thecross bar 21 extends to the right and left. The rod 22 is pivotallyjoined to a shaft 23 at its lower end, and a similar shaft 24 at itsupper end.

The distance between the shafts 4 and 23 on the fixed arm 20 is equal tothat between the shafts 18 and 24 at the elbow 16. Additionally, thelever is of the same length, as the rod 22.

Continuing on with FIG. 1, a mounting plate 25 is carried intermediatethe ends of an arm 26. The arm 26 is connected at its back end as shownin FIG. 1 to the lower end of the lever. 15 by means of a shaft 27. Theshaft 27 is similar in construction to the shaft 4 previously mentioned.A rod 28 having the same length as the lever 15 is connected to theupper end of the mounting plate 25, and to the left hand end, as viewedin FIG. 1, of the uppermost part 21 of the elbow 16. A shaft 29 is foundat the upper end of the rod 28 while the shaft 30 completes the lowerend pivotal connection. The distance between the shafts 27 and 30 on thearm 26 is equal to the distance between the shafts l9 and 29 on theelbow 16.

The arm 26 carries near its outer end a rotary cylinder 31, and a clampchuck 33 which is opened and closed by movement of a clamp cylinder 32.

' Directing attention to the side view of FIG. 1, the handling machineas hereinbefore described includes a parallelogram defined by the linesconnecting the shafts 18 and 24, 24 and 23, 23 and 4, and 4 and 18, orthat which is represented by the points A, B, C, and D, in FIG. 4. Anadditional parallelogram is defined by the lines connecting the shafts19 and 29, 29 and 30, 30 and 27, and 27 and 19, or that which isrepresented by the points E, F, G, and H, in FIG. 4. The twoparallelograms are symmetrical with respect to a vertical line V 4 Vwhich passes through the midpoint of a line drawn from the points A to Ein FIG. 4.

In operation, the hydraulic cylinder 9 causes extension and retractionof the mechanical arm. When the piston rod is in its retracted positionas shown in FIG. 1, both the levers 5 and are in the withdrawn ororiginal upright position as" shown in solid line in FIG. 4. The angleof inclination a of the fixed support arm with respect to a horizontalline, hereinafter called the angle of inclination of the supportingmember 20, and the angle of inclination B of the line connecting theshafts and 27 on the arm 26 with respect to a horizontal line,hereinafter called the angle of inclination of the arm 26 are equal toeach other. As will be amply pointed out hereinafter, the arm 26 staysin the horizontal position while the angles a and B remain equal.

As the piston rod 10 moves downwardly and somewhat forwardly as viewedin FIG. l,'the lever 5 rotates counterclockwise by an angle 0 to aposition shown in dot-dash line in FIG. 4. The parallel motion mechanismincluding the points A, B, C, and D, in FIG. 4, moves the elbow 16 inparallel movement to that of the horizontal line between the points H toD whereby the engagement of the segment gears 13 and 14 causes the lever15 to turn clockwise by the same angle 0 as shown in FIG. 4.Accordingly, the parallelogram defined by the lines connecting thepoints A,, B,, C and D, which is formed by the movement or distorsion ofthe upper portion of the parallelogram A B C D, and the parallelogramdefined by the lines connecting the points E F G and H which is formedby movement of the parallelogram E F G H, are symmetrical with eachother with respect to the vertical line V V,, passing through the middlepoint of the line drawn between the points A and E in FIG. 4. Thus, theangle of inclination a of the supporting member 20 and the new angle ofinclination B of the arm 26 are equal to each other at the intermediateposition achieved by movement of the lever 5 through the angle 0 in thesame manner as when the mechanism is in the retracted positionrepresented by the full solid lines of FIG. 4. The arm 26 has beenadvanced by the distance L; from its original position, still remaininghorizontal.

Consider next the possibility that the piston rod 10 extends furtherdownwardly and toward the left as viewed in FIG. 1. The lever 5 turnscounterclockwise further to the angle represented by 0 which is shown inbroken line in FIG. 4. The elbow member 16 again moves to a positionparallel to the base line extending from the point H to the point D. Theengagement of the gears 13 and 14 causes the lever 15 to turn againclockwise to an angle 6 as shown in FIG. 4. A new parallelogram definedby the lines connecting points A B C and D, is formed. Theparallelogramfor the second lever is defined by the lines E F G and H Theparallelograms are still symmetrical with each other with respect to thevertical lines V V which passes through the midpoint of a line betweenthe points E and A in FIG. 4. Accordingly, the angle of inclination a ofthe fixed support arm 20, and the new angle B of the arm 26 are stillequal to each other, and the arm 26 still remains horizontal, but isfound in a position advanced by the distance L; from its originalposition.

The piston rod 10 continues to extend until the lever 5 is turned fromits original upright position to a point where the arm is in its fullystretched position and forms a horizontal straight line with the levers5 and 15 aligned in the manner shown in FIG. 2.

On the other hand, as the piston rod 10 is retracted and the lever 5returns to the position shown in solid line of FIG. 4, the parallelmotion mechanism illustrated in FIG. 4 causes the connecting elbow 16 tocontinue in parallel movement backward while the engagement of the gear13 with the gear 14 causes the lever 15 to move back in the same extentthat the lever 5 is retracted such that the arm 26 is caused to retreatalong the path it had taken previously when extended, and to movehorizontally back to its original position.

Reference is now made to FIG. 5 of the drawings, where a secondembodiment of the device of the present invention is illustrated. As inthe first embodiment of the device shown in FIGS. 1 4, the lower end ofthe lever S and the crank arm 6 are mounted respectively on a shaft 4which is rotatably carried by an upstanding bracket 3 on the bottomplate 2 of the support structure 1. The upper end of the cylinder 9 isfixed in the same manner as before, and the piston rod 10 functions inthe same manner. The mounting 8 carried on the bottom side of the topplate 7 supports the hydraulic cylinder 9. The shafts 11 and 12 arefound at opposite ends of the hydraulic cylinder 9.

Again, the lever 5 carries a gear segment 13 on its upper end, and agear 14 is engaged with the gear 13 at the upper end of the lever 15.

In the embodiment of FIG. 5, the levers 5 and 15 are equipped with thegears 13 and 14 at the upper end, respectively. The levers 5 and 15 arepivotally mounted respectively on the shafts 35 and 36 which are carriedby a connecting elbow or member 34, the shafts 35 and 36 beingpositioned to extend through the gears 13 and 14, respectively. Thegears 13 and 14 are shaped alike, and the levers 5 and 15 are adapted torotate in the same extent but in the opposite directions with respect tothe connecting elbow 34.

A sprocket wheel 37 is fixedly carried on the shaft 35 which alsocarries the gear 13. The shaft 4 fixedly supports an additional sprocketwheel 38 which is of the same size and dimensions as the sprocket wheel37, and which is coaxially mounted on the shaft 4. A chain 39 extendsaround the sprocket wheels 37 and 38. In the withdrawn position, theconnecting elbow 34 is horizontal while the levers 5 and 15 are in theupright position as shown in FIG. 5.

At the lower end of the lever 15, an arm 40 similar to the arm 26 shownin FIG. 1 is located. The arm 40 is fixedly carried on a shaft 41 forpivotal movement with respect to the lever 15. A sprocket wheel 43 isfixedly carried on the shaft 41. The elbow 34 supports an additionalsprocket, wheel 42 which is of the same shape and dimensions as thesprocket wheel 43, and which is coaxially mounted on the shaft 36. Thechain 44 extends around the sprocket wheels 43 and 44. The gear 14, thesprocket wheel 42, and the shaft 36 rotate as a unit. The same is alsotrue of the gear 13, the sprocket 37, and the shaft 35.

Operation of the second embodiment as shown in FIG. 5 will now bedescribed. The arm 40 is in the horizontal position shown in FIG. 5 whenthe levers 5 and 15 are in their upright positions. When the piston rod10 extends downwardly and causes the lever 5 to rotate counterclockwiseby an angle 0, the mechanism including the sprocket wheels 37 and 38 andthe chain 39, causes the connecting elbows to move in a parallelfashion. The engagement of the gears 13 and 14 causes the lever 15 torotate clockwise by the same angle, 9. Accordingly, the lower end of thelever 15 moves horizontally, maintaining its relative height as shown inFIG. 5. The motion of the lower end of the lever 15 is determined byoperation of the mechanism, including the sprocket wheels 42 and 43 andthe chain 44. Thus, the arm 40 is maintained parallel'with theconnecting elbow or member 34, and thus, the arm 40 remains horizontalthroughout its range of movements. Therefore, the arm 40 advanceshorizontally, or to the left in FIG. 5, as it is extended. It retreatshorizontally to the retracted position of FIG. 5 also. The lever 5 has arange of movement which is approximately 90 from its vertical or uprightposition of FIG. 5 until it is extended to the left in FIG. 5. Thevarious sprocket wheels and chain drive provide a positive systeminterconnecting the various components of the extendible arm mechanism.

Attention is next directed to FIG. 6 of the drawings which illustratesan additional embodiment of the present invention. In FIG. 6, the lever5 is mounted on a shaft 47 which extends through a fixed bracket 46 inthe top of a column shaped structure 45. A movable crank arm 49 extendsfrom the lever 5. The crank arm 49 is manipulated by means of thehydraulic cylinder 9. At the lower end, a support bracket 48 is joinedto the column shaped structure 45, and extends laterally to position apivot 50 for connection with the hydraulic cylinder 9. The piston rod 10extends toward the crank arm 49. The pivotal connection between thesetwo members is achieved through the use of a shaft or pin 51. In thefully retracted position of the piston rod, the lever 5 achieves anupright position as shown in FIG. 6. When the piston rod 10 is extended,the lever 5 turns counterclockwise from the position shown in FIG. 6.

The upper end of the lever 5 supports a bevelled gear 52. Attention istemporarily directed to FIG. 9 of the drawings which shows the upper endof the lever 5 which supports the bevel gear 52. A pin 54 extendsthrough the end of the lever 5 and supports the bevel gear 52. Anidentical bevel gear 53 is fixedly carried on the upper end of anadditional lever 15. As shown in FIG. 9, the levers 5 and 15 are bothmounted on the shaft 54 which extends through the gears 52 and 53. At anintermediate location between the bevel gears 52 and 53 is a connectingmember 57, analogous to the elbow member 16 in FIG. 1, which comprisestwo rods 55 and 56 which are joined at right angles to each other. Thisis more clearly shown in FIG. 6. The rods 55 and 56 comprise portions ofthe connecting member 57 which positions the rods at right angles toeach other. The connecting member 57 is mounted on the shaft 54 at apoint supporting the rods 55 and 56 at their intersection. The rod 55carries and supports an intermediate bevel gear 58 which meshes with thebevel gears 52 and 53. A bushing 59 supports the bevel gear 58 on therod 55. The gear 58 is rotatable about the rod 55 on which it issupported.

As shown in FIGS. 6 and 7, a rod 61 which is the same length as thelever 5, is supported at both ends. The lower end of the rod 61 isconnected with a fixed support arm 60 which projects from the columnarsupport structure 45. The rod 61 is supported at its upper .end by therod 55. Both connections are made pivotal through the use of connectiveshafts 62 and 63 at the upper and lower ends, respectively. The distancebetween the shafts 47 and 63 on the member 60 and the distance betweenthe shafts 54 and 62 on the rod 55 are equal to each other.

As shown in FIG. 9, retaining means 64, 65 and 66 secure the three gears52, 53 and 58 in engagement with one another. The shaft 54 supports apair of bushings 67 and 68 which are loosely mounted on the shaft 54 andwhich limit the range of movement of the connective bracket 57.

As shown in FIG. 7, the lower end of the lever 15 supports an arm 70.The connection is made by means of the shaft 71 which permits the arm 70to rotate with respect. to the lever 15. The arm 70 supports an upwardlyprojecting connecting member 69 and a rod 72 whichis of. the same lengthas the lever 15 is fixed at both ends. The lower end of the rod 72 isfixed to the upwardly projecting mounting bracket 69. The upper end ofthe rod 72 is joined to the rod 56 as previously mentioned. Through theuse of a pair of shafts 73 and 74, therod 72 is pivotally connected atboth ends. The distance between the shafts 54 and 73 on the rod 56,andthe distance between the shafts 71 and 74 on the arm 70 are equal.

The arm 70 carries a rotary cylinder and appropriate apparatus similarto that shown in FIG. 1 in the first embodiment. A clamp chuck 75 isshown in FIGS. 6 and7.

'In'the handling machine. shown in FIGS. 6 9, a first parallelograrnisdefined by lines joining the shafts 54, 62', 63 and 47. These are thepoints J, K, L, and M, respectively, shown in FIG. 10. A secondparallelogram is defined by lines joining the shafts 54, 73, 74 and 71,which are shown at points J, P, Q, and R, respectively, inFIG. 10. Thetwo parallelograms are symmetrical with respect to each other about thevertical line from the point J to either ofthe points M or R in FIG. 10.I Considering now the operation of the embodiment shown in FIGS. 6 9,the hydraulic cylinder 9 extends the piston rod 10. Withthe levers 5 and15 in their original'upright position as shown in solid line in FIG. 10,angles of inclination of the member 60 and the arm 70 are thus defined.The angle of inclination of the member 60 is defined as a while theangle of inclination'of the arm 70 is defined as B. The angles a and Bare equal to each other, and, of course, the arm 70 is held inthehorizontal position.

n application of hydraulic power to the cylinder 9, the piston rod 10.is-extended and the lever turns counterclockwise to an angle 0 as shownby the dot and dashlines in FIG. 10. The parallel motion mechanismrepresented by the parallelogram J K L M causes the connecting elbow ormember 57 to move in a parallel fashion and the bevel gear 52 rotatesthe intermediate bevel gear 58. Attention is momentarily directed toFIG. 6 of the drawings wherein the bevel gear 58 is shown rotating bythe angle 0 in the direction of the arrow X in FIG. 6. The rotation ofthe intermediate bevel gear causes the bevel gear 53 to rotate and thebevel gear 53 in turn causes the lever to move clockwise and incline byan angle 0 with respect to the vertical line V, V, passing through thepoint J, in FIG. 10. Consequently, the parallelogram J, K, L M which isformed after the movement of the para]- lelogram J K L M is symmetricalto the parallelogramJ, P, Q, R, which is formed after the movement ofthe parallelogram J P Q R. The two parallelograms formed after movementthrough the angle 0' are: symmetrical with respect to each other aboutthe vertical line V, V, The angle a of the support arm or member 60 andthe new angle B, of the arm 70 are equal to eachother inasmuch as themembers 60 and remain in their original angular positions shown in solidline in FIG. 10. Again, the arm 70 has advanced the distance L,horizontally, or to the left as viewed i FIG. 10. Considering theextension of the arm by an additional distance, the distance L, in FIG.10. Again, the hydraulic cylinder 9 is further operated to advance thepiston rod 10. The lever 5 is turned further counterclockwise through anangle 0 as shown with broken lines in FIG. 10. The connecting member 57.moves arcuately as shown in FIG. 10, but remains ever parallel to theline or path of rectilinear movement of the arm 70. Movement of theconnecting member 57 initiates operation of the bevel gear mechanismconnected between the levers 5 and 15. The bevel gear 52 causes theintermediate bevel gear 58 to rotate by the angle 0, in the direction ofthe arrow X in FIG. 6. The intermediate bevel gear 58 in turn causes thebevel gear 53 to rotate correspondingly, and the bevel gear 53, in turn,causes the lever 15 to turn or rotate clockwise to an angle 0, withrespect to the vertical line V V passing through the point J, in FIG.10. After rotation through the angle 0, a new parallelogram, J, K, L Mis defined. This parallelogram is associated with the lever 5. Anotherparallelogram, newly defined, and associated with the lever 15, islikewise formed at the points J P Q R The two parallelograms aresymmetrical with each other with respect to a vertical line V V Theangle of inclination a of the member 60 and the new angle [3 of the arm70 are equal to, each other even though the arm is moved through thedistance L, horizontally.

The mechanism which causes the levers 5 and 15 to move in a manner suchthat the arm- 50 remains horizontal is bidirectional in operation.Referring to the movement of the levers 5 and 15, and the arm 70 whichis both extended and retracted in FIG. 10, the mechanism can extend andreturn to the original solid line position shown in FIG. 10. Theparallel. motion mechanism illustrated in the drawings causes theconnecting member 57 to move in a parallel fashion back to its originalposition. The gears 52, 58 and 53 transfer the appropriate motion to thelever 15 to return it, ever maintaining the same angle with respect tothe lever 5, and return the lever 15 to the original position. Theretraction of the levers 5 and 15 causes the arm 70 to retreat along thepath which was followed when it was extended or moved horizontally. Itwill be appreciated that the intermediate bevel gear 58 which mesheswith the bevel gears 52 and 53 is rotated in the direction opposite thatof the arrow X of FIG. 6 on retraction.

An economy of components in construction is achieved by utilizing theconnecting member 57 to also support the bevel gear 58. Obviously, thegear 58 can be located at other points so long as it maintains a meshedinterconnection with the two gears 52 and 53.

The three embodiments which are shown function in a similar manner. Forinstance, the embodiment 5 utilizes the chain 39 instead of the push rod22 shown in FIG. 1. Obviously, a push rod suchas that shown in FIG. 1can be both push and pull. While a link chain or other similar apparatusfunctions only in tension, the chain extends on both sides of the lever5 in FIG. 5 and tension on the portion of the chain to the left of thelever 5 corresponds to compression on the push rod 22 together thelevers Sand in the first embodiment.

While it is of slightly different construction in FIG. 5, the connectivemember 34 functions in the same manner as the elbow mentioned withregard to the embodiment of FIGS. 1 4, inclusive. Even further, the sameis true of the connective member 57 illustrated in the last embodimentdescribed.

As heretofore described by way of several embodiments, the severalinvention is intended to provide a new and improved device for causingthe arm of a mechanical handling machine to move in a horizontal,rectilinear direction. The device normally includes a support structurefor mounting the mechanical handling machine. The apparatus incorporatesa pair of levers which move or deflect through symmetrical angles,keeping in view that the levers are connected by a type of elbowmechanism. The elbow mechanism transfers a certain type of movement fromthe first lever to the second. The mechanical handling machine utilizesstiff links, pulleys, belts, sprockets and chains, or the like, formaintaining each armed segment in a particular relationship to the otherarmed segments. A pair of symmetrical and similar parallel motionparallelograms are thusly incorporated in the structure describing thefirst pair of armed segments. Quite clearly, many differentsubstitutions and alterations in the present invention may be readilyaccommodated- The scope of the present invention is determined by theclaims which are appended hereto.

What is claimed is:

1. Handling apparatus comprising:

a base;

a first arm having one end portion pivotally coupled to said base forrotation about a first axis perpendicular to a predetermined plane;

a rigid link member having one end portion pivotally coupled to theother end portion of said first arm for rotation about a second axisperpendicular to said plane;

a second arm having one end portion pivotally coupled to the otherendportion of said link member for rotation about a third axisperpendicular to said plane;

selectively-operable handling means coupled to the other end portion ofsaid second arm;

. actuating means operatively coupled to said first arm and adaptedfor-selectively rotating said first arm between selected angularpositions lying in said plane; and

motion-controlling means adapted for limiting movement of said handlingmeans to rectilinear motion upon rotation of said first .arrn betweenits said selected positions, said motion-controlling means including afirst pair of rigid members'respe ctively coupled to said one endportion of said first arm and of said link member and respectivelyhaving portions thereof extending outwardly equal distances and at equalangles to said first arm for defining a first pair of pivotsrespectively having a pivot axis perpendicular to said plane,

a second pair of rigid members respectively coupled to said other endportion of said second arm and of said link member and respectivelyhaving portions thereof extending outwardly equal distances and at equalangles to said second arm for defining a second pair of pivotsrespectively having a pivot axis perpendicular to said plane,

first and second tension members respectively coupled between said pivotaxes of said first and second pairs of said rigid members andrespectively extending parallel to said first and second arms, and

gear means operatively arranged for transmitting rotative movementbetween said other end portion of said first arm and said one portion ofsaid second arm upon rotation of said first arm between its saidpositions to move said handling means along a straight line.

2. The handling apparatus of claim 1 wherein said handling means includematerial-gripping means and selectively-operable means for actuatingsaid materialgripping means.

3. The handling apparatus of claim 1 wherein said first and second pairsof rigid members are comprised of outstanding brackets respectivelyhaving said first and second pairs of pivots respectively lying in saidpivot axes; and said first and second tension members are comprised ofrigid members respectively pivotally coupled to said pivots.

4. The handling apparatus of claim 1 wherein said first and second pairsof rigid members are comprised of first and second pairs of circulargears respectively mounted on the axes at each end portion of said firstand second arms and respectively havingte eth. in a circle concentricwith said pivot axes'f'and said first and second tension members arecomprised of first and second sprocket chains respectively loopedaroundsaid first and second pairs of circular gears for carrying tension loadsbetween said pivot axes as defined by said gear teeth.

5. The handling apparatus of claim 1 wherein said first and second armslie in said predetermined plane so that said handling means will bemoved in said predetermined plane; and wherein said gear means includefirst and second intermeshed gears respectively lying in saidpredetermined plane.

6. The handling apparatus of claim 5 wherein said first and second pairsof rigid members are comprised of outstanding brackets respectivelyhaving first and second pairs of pivots respectively lying in said pivotaxes; and said first and second tension members are comprised of rigidmembers respectively pivotally coupled to said pivots.

7. Handling apparatus comprising a. a base;

b. a first arm having one end portion pivotally coupled to said base forrotation about a first axis;

c. a link member having at least two connective portions with one ofsaid connective portions connected to the free end portion of said firstarm;

d. a second arm having one end portion connected to the other connectiveportion of said Iink'member;

e. selectively operable handling means coupled to the other end portionof said second arm;

f. actuating means operatively coupled to said first arm and adapted forselectively rotating said first arm between selected angular positions;

motion-controlling means adapted for limiting movement of said handlingmeans to rectilinear 5 motion upon rotation of said first arm betweenits selected positions, said motion-controlling means including:

i. a first pair of rigid members operatively respectively coupled tosaid one end portion and connective portion of said first arm and saidlink member, and each extending outwardly equal distances and at equalangles to said first arm for defining a first pair of pivots;

. a second pair of rigid members operatively respectively coupled to theother end portion and connective portion of said second arm and saidlink member, and each extending outwardly equal distances and at equalangles to said second arm for defining a second pair of pivots;

iii. first and second tension members respectively coupled said pivotaxes of said first and second pairs of rigid members and respectivelyextending parallel to said first and second arms; and

iv. gear means operatively arranged for transmitting rotative movementfrom the free end of said first arm to the one end portion of saidsecond arm upon rotation of said arm between its positions to move saidhandling means along a straight line. Y

8. The handling apparatus of claim 7 wherein said first and second armslie in first and second spaced planes parallel to a predetermined planeso that said handling means will be moved in said second plane; andwherein said gear means include first and second bevel gearsrespectively arranged on said first and second arms for rotation in saidfirst and second planes, and a third bevel gear cooperatively arrangedbetween said first and second bevel gears for rotation in a planeperpendicular to said first and second planes.

9. The handling apparatus of claim 8 wherein said first and second pairsof rigid members are comprised of outstanding brackets respectivelyhaving said first and second pairs of pivots respectively lying in saidpivot axes; and said first and secondtension members are comprised ofrigid members respectively pivotally coupled to said pivots.

v UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 a731 820 Dated M81 8 1973 i Akira Niki et a1. Inventor(s) It is certifiedthat error appears in the above-identified patent and that said "LettersPatent are hereby corrected as shown below:

On the cover sheet I75] "Akili Niki" should read Akira Niki Signed andsealed this 29th day of January 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer ActingCommissioner of Patents FORM 90-1105?) (10- 9) v USCOMM-DC e oavv pes VU.S. GOVERNMENT PRIRTING QFHCE "l9 O366-33

1. Handling apparatus comprising: a base; a first arm having one endportion pivotally coupled to said base for rotation about a first axisperpendicular to a predetermined plane; a rigid link member having oneend portion pivotally coupled to the other end portion of said first armfor rotation about a second axis perpendicular to said plane; a secondarm having one end portion pivotally coupled to the other end portion ofsaid link member for rotation about a third axis perpendicular to saidplane; selectively-operable handling means coupled to the other endportion of said second arm; actuating means operatively coupled to saidfirst arm and adapted for selectively rotating said first arm betweenselected angular positions lying in said plane; and motion-controllingmeans adapted for limiting movement of said handling means torectilinear motion upon rotation of said first arm between its saidselected positions, said motioncontrolling means including a first pairof rigid members respectively coupled to said one end portion of saidfirst arm and of said link member and respectively having portionsthereof extending outwardly equal distances and at equal angles to saidfirst arm for defining a first pair of pivots respectively having apivot axis perpendicular to said plane, a second pair of rigid membersrespectively coupled to said other end portion of said second arm and ofsaid link member and respectively having portions thereof extendingoutwardly equal distances and at equal angles to said second arm fordefining a second pair of pivots respectively having a pivot axisperpendicular to said plane, first and second tension membersrespectively coupled between said pivot axes of said first and secondpairs of said rigid members and respectively extending parallel to saidfirst and second arms, and gear means operatively arranged fortransmitting rotative movement between said other end portion of saidfirst arm and said one portion of said second arm upon rotation of saidfirst arm between its said positions to move said handling means along astraight line.
 2. The handling apparatus of claim 1 wherein saidhandling means include material-gripping means and selectively-operablemeans for actuating said material-gripping means.
 3. The handlingapparatus of claim 1 wherein said first and second pairs of rigidmembers are comprised of outstanding brackets respectively having saidfirst and second pairs of pivots respectively lying in said pivot axes;and said first and second tension members are comprised of rigid membersrespectively pivotally coupled to said pivots.
 4. The handling apparatusof claim 1 wherein said first and second pairs of rigid members arecomprised of first and second pairs of circular gears respectivelymounted on the axes at each end portion of said first and second armsand respectively having teeth in a circle concentric with said pivotaxes; and said first and second tension members are comprised of firstand second sprocket chains respectively looped around said first andsecond pairs of circular gears for carrying tension loads between saidpivot axes as defined by said gear teeth.
 5. The handling apparatus ofclaim 1 wherein said first and second arms lie in said predeterminedplane so that said handling means will be moved in said predeterminedplane; and wherein said gear means include first and second intermeshedgears respectively lying in said predetermined plane.
 6. The handlingapparatus of claim 5 wherein said first and second pairs of rigidmembers are comprised of outstanding brackets respectively having firstand second pairs of pivots respectively lying in said pivot axes; andsaid first and second tension members are comprised of rigid membersrespectively pivotally coupled to said pivots.
 7. Handling apparatuscomprising a. a base; b. a first arm having one end portion pivotallycoupled to said base for rotation about a first axis; c. a link memberhaving at least two connective portions with one of said connectiveportions connected to the free end portion of said first arm; d. asecond arm having one end portion connected to the other connectiveportion of said link member; e. selectively operable handling meanscoupled to the other end portion of said second arm; f. actuating meansoperatively coupled to said first arm and adapted for selectivelyrotating said first arm between selected angular positions; g.motion-controlling means adapted for limiting movement of said handlingmeans to rectilinear motion upon rotation of said first arm between itsselected positions, said motion-controlling means including: i. a firstpair of rigid members operatively respectively coupled to said one endportion and connective portion of said first arm and said link member,and each extending outwardly equal distances and at equal angles to saidfirst arm for defining a first pair of pivots; ii. a second pair ofrigid members operatively respectively coupled to the other end portionand connective portion of said second arm and said link member, and eachextending outwardly equal distances and at equal angles to said secondarm for defining a second pair of pivots; iii. first and second tensionmembers respectively coupled said pivot axes of sAid first and secondpairs of rigid members and respectively extending parallel to said firstand second arms; and iv. gear means operatively arranged fortransmitting rotative movement from the free end of said first arm tothe one end portion of said second arm upon rotation of said arm betweenits positions to move said handling means along a straight line.
 8. Thehandling apparatus of claim 7 wherein said first and second arms lie infirst and second spaced planes parallel to a predetermined plane so thatsaid handling means will be moved in said second plane; and wherein saidgear means include first and second bevel gears respectively arranged onsaid first and second arms for rotation in said first and second planes,and a third bevel gear cooperatively arranged between said first andsecond bevel gears for rotation in a plane perpendicular to said firstand second planes.
 9. The handling apparatus of claim 8 wherein saidfirst and second pairs of rigid members are comprised of outstandingbrackets respectively having said first and second pairs of pivotsrespectively lying in said pivot axes; and said first and second tensionmembers are comprised of rigid members respectively pivotally coupled tosaid pivots.